Hitherto, it is known that for improving the soundproof property, weather resistance, non-sticking property, antifreezing property, slipping property, and abrasion resistance of a weather strip for automobiles, the weather strip can be subjected to a surface treatment with a silicone.
In general, it is known to use a reaction product or a mixture of epoxysilane and aminosilane (as described in JP-A52-123394, JP-A-54-43891, JP-A-54-90375, JP-A-56-78960, JP-A61-159427, and JP-A-2-233763) (the term "JP-A" as used herein means an "unexamined published Japanese patent application") and a silicone resin as a surface treating agent for a weather strip, but since these compositions are generally in the form of an organic solvent solution, when such composition are used, there is a problems of environmental pollution in addition to the problems of hygienic safety and careful handling owing to inflammability. Accordingly, the development of an emulsion type coating composition without using an organic solvent has been required.
On the other hand, silicone emulsions have hitherto been widely used as a mold release agent, a lustering agent, and a fiber treating agent, but when such silicone emulsions are used as coating compositions for weather strips, they are poor in durability and adhesion. Also, amino functional silicone emulsions which are said to have a high durability (as described in JP-A-60-127382, JP-A-62-116633, and JP-A-63-66265), a mixture of aminosiloxane and epoxysiloxane (as described in JP-B-48-17514) (the term "JP-B" as used herein means an "examined published Japanese patent application"), and a reaction product of aminosiloxane and epoxysilane (JP-B-1-22390) are proposed as a surface treating agent for weather strips but the weather strips surface treated with the above surface treating agents do not satisfy the properties such as a soundproof property, a slipping property, etc., required for the weather strips.
The reaction product or the mixture of epoxysiloxane and aminosilane dissolved in an organic solvent, which have hitherto been used, can be emulsified with a proper emulsifier. However, the weather strips coated with the emulsified product described above do not satisfy the required properties describe above.
Also, a coating composition comprising aminosiloxane and epoxysilane has compounded therewith a condensation curing reaction catalyst such as an organotin compound, an organotitanium compound, etc., and thus there are problems that the pot life of the coating liquid is short, when the respective components are compounded and the resulting mixture is stirred at a high speed to prepare the coating liquid, a gel is liable to form, and pipes are liable to be clogged with the coating liquid. Thus, an improvement has been required.
Also, a spray coating method, a dip coating method, a felt coating method, etc., are known as a method of applying a coating composition on the weather strips. However, in the dip coating method, a coating composition is liable to drip and, as the case may be, the appearance and the abrasion resistance become insufficient.
On the other hand, in the felt coating method, the problem of dripping of a coating composition does not occur but there are problems that the coating composition is cured in the felt, etc. Also, in the spray coating method, there are problems of causing clogging of a nozzle, etc.